Since I am still online for a bit I take the liberty of adding a couple of considerations:

@Axel: very well said, yet do you know how a Zen master would have answered to a pupil asking those questions? :-)

@Matthew: you're right, it's the mind. If you can keep your eyes open against incoming and landing blows and you can still look straight into the face a charging opponent, you will be surprised at how infinitely more effective you will be in defending yourself.
Actually, I personally believe that a combat oriented style is more geared, possibily, to teach you this attitude and ability rather than a technique or another.